Algodoo

Well done! How did you set the moon-velocity to make him orbit around the planet? Please set a hint in the scene that the moon is a the planet in 4 o'clock starting position relatively to the sun. And add some contrast (planets relatively to the background) please.

@ DrBalk... I copied the sun and innermost planet and placed them waaaay far out away from the sun and they both gradually drew closer toward the original sun. Then once their trajectory looked like a good speed, I moved them closer to the original sun with the direction perpendicular to the original sun so that they would both "ride into" the orbital path together while maintaining the orbit.

@DrBalk... Yes that's a good idea to add contrast. I added the contrast and an indicator showing the little planet with the moon. It looks better now.

NOTICE!!! This is planetarium 2. Not the one with the moon. That one is simply called Planetarium. The comments are left over from this being created from a copy of the original planetarium. If anyone wishes to see the one with the moon, just look up "Planetarium" under my scenes. --- Norg

Disreguard previous comment. I'm gonna upload the 3-planet one with the controllable planet separately in a bit. sorry